Preheat the oven to 350°F.
Carefully break each noodle in half and dice the onion.
Fry the onion and ground beef in a medium skillet for a few minutes until beef is browned, breaking up any clumped meat. Drain and return to the pan.
Add in the garlic, Italian seasoning, and salt. Stir in the tomato sauce and simmer over low heat for 5 minutes.
At the same time, in a small bowl, whisk together the egg, ricotta and parmesan.
In the bottom of two individual 10 ounce square oven safe baking dishes, place about 1 tablespoon of the meat sauce across the bottoms of each pan.
Top the sauce with one half noodle in each dish.
Spread the ricotta mixture over the noodles in each dish, divided evenly.
Then top with ½ of the remaining meat sauce mixture, divided evenly.
Add another half noodle to each dish.
Spread remaining ricotta mixture over each noodle
Layer on the remaining sauce, divided evenly.
Top each with the shredded mozzarella, divided evenly between each dish.
Loosely tent the dishes with foil and bake for 40 minutes.
Remove foil and bake another 10 minutes, allowing cheese to brown.
Let cool for about 15 minutes before serving.